Smart underpinning combined with support tower

As project TwoTwoFive rapidly rises from the ground, attention to what went on underneath the building has all but disappeared. Yet a structural feat has been performed here. It took PW Bouwgroep over three-quarters of a year of preparation to complete the construction of the three-story underground parking garage in the thirteen weeks allotted for it.

In fact, TwoTwoFive's parking garage is not that different from the average underground parking garage, but because of the ultra-short time frame, PW Bouwgroep had to come up with the fastest possible working method for this. "The thirteen weeks were only feasible with very efficient working methods and smart underpinning," explains Ruben Paauw of PW Bouwgroep. "In the end we succeeded with a support construction in which the channel and wide slab floors were poured in one shift."

Intensive preparation

In order not to lose precious time during execution, the entire project was prepared in every detail. Every possible obstacle was tackled in advance. "For this, we worked intensively with Heddes Bouw," says Paauw. "We spent more than three-quarters of a year having preparatory discussions with each other and looking together for the method by which we could save the most time. In this way, we found out fairly quickly that a traditional construction system would not work under the circumstances."

Full customization

Instead - in consultation with formwork specialist Doka - a support stamping system combined with a Staxo tower was chosen. "We are then talking about a very strong and quick to place support system," Paauw explains. "This is specially designed for great heights and depths like in TwoTwoFive. Yet the system is easy to build, relatively lightweight and therefore labor-friendly." In addition, all formwork was custom-made, including those for the concrete walls in the basement and the structural columns. This ensured the highest possible work rate.

Tight logistics plan

Yet construction was not the only challenge. The space around the parking garage to be built was limited and this required a tight logistics plan with sufficient space for all parties involved. In practice, this meant that all materials had to be delivered just-in-time. Paauw: "The development of this plan also required quite a bit of creativity, but ultimately all the planning together ensured that we were able to deliver the parking garage after thirteen weeks."